Webgrid

-------------------------

- enable default_op processing for all filter types

-------------------------

- BC break: replaced MultiSelect widget with multipleSelect plugin.
Related JS and CSS must be included (available in webgrid static)
- included missing images referenced by webgrid CSS

-------------------------

- updated filter tests to work with SA0.9
- refactoring related to subtotaling feature
- adjustments for SQLAlchemy 0.9+ (we now support 0.8+)
- workaround for dateutils parsing bug
- testing fixes
- completed dev requirements list
- fixed nose plugin bug, must not assume pathname case consistency (Windows)
- added BlazeWeb adapter
- xls_as_response now an adapter method, called by XLS renderer
- render_template now an optional adapter method, falls back to Jinja2 call

-------------------------

- fix nose plugin setup to avoid warning message
- fix javascript bug related to sorting & newer jQuery libraries
- fix SA expression test to avoid boolean ambiguity
- avoid accidental unicode to text conversion in filters

-------------------------

- fix string/unicode handling to avoid coercion of unicode to ascii

-------------------------

- adjust the way the Flask blueprint is created and registered
- adjust route on blueprint so it has /static/... prefix for URL